The African Union says three of its peacekeepers in Darfur were wounded Wednesday when they were fired on by members of a former Darfur rebel group.

An AU statement Thursday says the incident happened after a vehicle crash between an AU armored personnel carrier and a convoy of the former rebel Sudan Liberation Movement, or SLM.

The statement says the crash killed one SLM member and wounded nine others, four of whom are in critical condition.

The African Union says the gunmen opened fire after demanding the surrender of AU vehicles and troops. The AU says its peacekeepers did not shoot back out of fear that nearby civilians would be harmed.

The SLM gunmen belong to a faction headed by Minni Minawi, the only Darfur rebel leader who signed a May 2006 peace deal with the Sudanese government.

That deal has done little to stop the violence in Darfur. Rebel groups continue to battle both the Sudanese military and government-backed militias. More than four years of fighting in the region has killed an estimated 200,000 people.